In a cataclysmic binary, a more-or-less normal star orbits a white dwarf so closely that matter spills from the normal star onto the white dwarf. A rich variety of behaviors results -- nova explosions, dwarf nova outbursts, accretion disk precession, magnetic channeling of the accretion flows, and much more. The light grasp and instrumentation at MDM Observatory are well-suited to studies of these objects. For decades now, we have used these facilities to characterize the cataclysmic binary...
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Stellar Population research is conducted to study the early formation history of our Milky Way galaxy and nearby satellite galaxies. Computational stellar models are compared to observations from the Hubble Space Telescope and other optical/infrared telescopes to determine the ages of stars.
FACULTY CONTACT: Brian Chaboyer
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We are part of a team that has discovered a population of extreme starburst galaxies with star formation densities millions of times higher than in our Milky Way. These galaxies are associated with winds being launched at thousands of km/s into the intergalactic medium, and appear to represent the most extreme possible conditions for star formation in the Universe. Our team is using a combination of optical, X-ray, and IR observations with Hubble, Chandra, Spitzer, and WISE, along with...
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One idea for the formation of supermassive black holes is that they grew from lower-mass "seeds" that formed in the first generation of galaxies in the early Universe. In this scenario, some such seed black holes should remain today and provide a "fossil" record of the early cosmic formation of black holes. We are studying a candidate "intermediate-mass" black hole in a nearby dwarf starburst galaxy, using X-ray observations with the Chandra, XMM-Newton, and ASCA observatories, to help...
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The luminous radiation from growing supermassive black holes (known as "active galactic nuclei" or "AGN") is effective at photoionizing the gas clouds in the host galaxy, producing huge ionized nebulae (or "narrow-line regions") glowing like fluorescent lamps that are thousands of light-years across. We are investigating the physical processes that form these nebulae, by measuring their physical sizes using optical spectroscopy from the Southern African Large Telescope (SALT) and MDM...
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In the past decade it has become increasingly clear that the cosmic evolution of galaxies is linked to the growth of their central supermassive black holes, but the nature of this connection remains poorly understood. We are using various techniques, including groundbreaking far-infrared observations from the Herschel Space Observatory, to measure the rate at which galaxies form stars, and connect this to measures of black hole accretion from Chandra X-ray Observatory and Spitzer Space...
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Quasars are among the most luminous and powerful objects in the Universe, powered by the accretion of matter onto supermassive black holes that reside at the centers of galaxies. While these amazing objects have been studied in depth since the 1960's, a large fraction of the quasar population has long been "missing", hidden by an obscuring screen of gas and dust. We are using powerful new infrared and X-ray observatories, in particular the Wide-Field Infrared Survey Explorer (WISE) and...
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A telescope mounted on a lighter-than-air platform (balloon) at an altitude above 60,000 ft would be above all clouds and weather and would offer imaging quality nearly on par with spacecraft like the Hubble Space Telescope. We are part of a group of Caltech and JPL scientists and engineers investigating the possibility of building a high-altitude, long duration vehicle platform for atmospheric and astronomy that would offer a new, much lower-cost access to near-space conditions.
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Some types of stars end their lives in highly energetic explosions known as supernovae. Over the past 75 years, astronomers have discovered nearly three hundred remnants of supernovae in our Milky Way galaxy, and over a 1000 remnants in several neighboring galaxies. Many key properties of supernova remnants depend on knowing the remnant's distance from us, a quantity that is hard to accurately measure. Since distances to stars is relatively easy to determine with good precision, we have...
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Stars around 10 times or more massive than our Sun end their lives when they run out of light elements to convert into heavier elements thus making energy. When they run out of such nuclear fuel, the star's central regions collapse under the weight of the layers above, crushing the gas forming a neutron star which ironically releases more energy than the star produced during its entire lifetime. Such stellar deaths are seen as supernova outbursts. Our knowledge about many of the important...
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